Frequently a proper choice of projection, scale, orientation
and coordinates is crucial for a map to convey its message
quickly and unequivocally, as demonstrated by a few examples.
When a reference is presented, the maps in this section are
not scannings or reproductions but rather approximate reconstructions
of the original sources (for instance, the original faunal
regions map does not use an equal-area projection) for
illustration purposes.
Faunal Regions and Global Connections
Major Faunal Regions of the World
Neartic
Palaearctic
Ethiopian
Neotropical
Oriental
Australasian
Oceanic
Faunistic division of the
world, modified Maurer projection
For zoological classification purposes, the world is divided
in faunal regions.
Here (after Oliver L. Austin and Arthur Singer, Birds of
the World, Hamlyn Publ. 1968), a map based on Maurer's star
projection
presents all lands minus Antarctica. Since climate is a great
determinant of faunistic features, most regional borders follow
latitudes and are, therefore, roughly concentric in
polar-aspect maps.
A land arrangement similar to the previous starlike map is
employed in the latest version of Buckminster Fuller's
icosahedral
projection. It was used for presenting fiber cable routes
and intercontinental network traffic in Thomas B. Allen's
The Future is Calling, National Geographic 200(6),
December 2001. The projection choice was appropriate, since
connections to Antarctica are negligible and no routing lines had to be
broken, even across oceans.
Migration Paths
Possible migration of early human population, according
to the "Out of Africa" hypothesis; clipped
Mercator map,
central meridian 150°E
According to the "Out of Africa" theory, modern man appeared
as a single African species nearly 100000 years ago, then
spread throughout the world (K.Wong,
Is Out of Africa Going Out the Door?,
Scientific American 281(2), August 1999).
A simple coordinate rotation avoids cutting the migration
path between Asia and Alaska.
Present and fossil teeth suggest
several migration waves in the past, when reduced sea levels
created bridges between
now isolated Japanese and Aleutian islands.
Cassini projection.
Some particular migration paths relate populations in eastern Asia
which may have later populated Polynesia, northern Asia and the
Americas. Dental anthropology (Christy G. Turner II, Teeth and
Prehistory in Asia, Scientific American 260 (2), February 1989)
provides evidence depending on several genetic factors, not culturally
acquired and seldom affected by the environment.
Mapping Puns
J.P.Snyder's hourglass-shaped projection.
Sometimes, serious cartographers resort to humor in order to make ideas
convincing. For instance, John P. Snyder, a prolific and influential
author of books, papers and projections, also created an equal-area
projection with absolutely no applicability other than evidencing that
areal preservation alone does not make a good projection, as some
supporters of Arno Peters's projection
apparently believe.
Snyder's whimsical proposal, devised ca. 1945 and informally presented
in 1987, is a
pseudocylindrical design with zero horizontal scale at the
Equator, and extreme vertical stretching to compensate. Reciprocally,
it is
flat-polar, with infinite horizontal scale at both poles. The
resulting map resembles an hourglass, with shape distortion much stronger
than in the unrelated Collignon map when drawn
with two flat poles.
Collignon's projection in the variant with two flat poles
Martin Gardner mentions a geographer being given an award (1973) in
the form of a framed map shaped as a bowtie (a favorite of his) drafted
by Waldo Tobler, another prolific author. Gardner does not disclose the
projection, but it could be a variation of Tissot's design for local
maps, referred to by Tobler in 1974.
Tissot's projection for local maps, expanded to the 3rd degree; reference latitude 0°. The map may assume stranger shapes, even intersecting itself for some reference latitudes; definitely this is not a projection for world maps.
Tissot's projection, reference latitude 90°S.
Orbital Tracks
Part of a great circle in an
equidistant cylindrical projection
The same curve in an orthographic
map
The crash of the Mir space station on the Pacific Ocean
attracted a lot of attention. Most media coverage used cylindrical projections to depict
the station's last moments following an apparently sinuous
curve. Of course, the actual path of a low-orbit object looks
much more simple when presented tridimensionally or as an azimuthal
orthographic map:
Despite popular conceptions and illustrations, many satellites
cruise at relatively low orbits, nearly grazing Earth's top
atmosphere: a typical average altitude for Mir and the International
Space Station is 390 km, while the Space Shuttle routinely
performs orbits below 250 km
(geostationary satellites ride much higher, at nearly 36000 km).
The example is
simplified, since orbiting objects neither follow exactly
circular trajectories nor keep constant altitude; besides, the
planet itself does not lie still but rotates beneath their
paths.
The curve separating day/night areas is also roughly a great
circle, thus the sinuous graphics in popular desktop programs
displaying a "sun clock" on rectangular maps.
Heavenly Maps
For most of mankind's history, stars and planets were mainly an
aid for navigation and time reckoning. In this role, it is
perfectly appropriate thinking of heavenly bodies as attached
to an enormous spherical shell slowly rotating around Earth.
Such a sphere can be mapped by exactly the same processes as
used for ordinary maps. In fact, some map projections were
first used by early astronomers for charting the skies instead
of lands.
Sky in boreal hemisphere
Sky in austral hemisphere sky
Two polar azimuthal stereographic maps
present the night sky as seen in the north and south poles.
Viewers in other latitudes and dates will see the
constellations more or less tilted.
In the boreal (northern) sky map, the Big Dipper appears at
the 9 o'clock position, at the second innermost circle. The
bright star at 10 o'clock is Arcturus; the Polar star is
slightly below the heavenly North pole. In the austral
(southern) sky, the two bright stars at 2 o'clock on the second
innermost circle belong to Centaurus and point to the Southern
Cross, slightly below and to the right; Sirius is the brightest
star near the bottom center.
